My boy, Carl Sagan, suggested that we go to one of the watery moons of Jupiter and fire pieces of it from electromagnetic railguns. The chunks of ice would be useful in themselves, but the moons orbit would also gradually change, eventually slamming into Venus. If done right, you could increase the planets spin rate, and deposit a heckuva lot of water into the atmosphere, cooling and de-acidifying it. In a few millenia, presto, a new earth!
Objections to “fixing” Venus
- Period of rotation
The planet takes ~180 days to spin. The mind boggling amount of energy required to speed up the planet far outweighs any benefit you would eventually get from it. For example smashing Venus with an asteroid would have next to no impact on its rotational period. Orbital mirrors require station keeping and maintenance. - Lack of water
I remember a number like the total water available at Venus would make a planet covering ocean 2 inches deep the covered the planet. Not nearly enough for airborne algae to do anything in the atmosphere except die. Sure you could fire some in from Europa but then you’re heating the atmosphere as you arrive - Massive atmosphere
Venus has an atmosphere 5 times that of Earths. Where exactly shall we precipitate out the gases? If and when you do, how do you keep them from gassing out again. Remember no water so you can’t simply lock them away as carbonates. - Massive heat
How do you radiate off a 900 degree planet when half of it is being baked by the sun. Station keeping of sun shades helps but the atmosphere acts as an insulating blanket that mitigates the heat loss.
But it’s a dry heat…
It would only be worth doing if the rest of the solar systems that we observe in the near future tend to have many more Venus type planets than Earth- type planets; this cretainly seems very likely to me.
In this case it is worth experimenting on Venus.
The L1 Lagrange point of Venus is a good place to put the sunshade; it will constantly be propelled toward our sister planet by light pressure, but if it is constructed as an energy-collection swarm it could intercept enought energy to maintain station by itself…
(assuming some improvements in the cost effectiveness of solar collection photo-voltaic systems- see this thread)
the swarm could be perhaps manufactured on Mercury or the Moon…
It would be nice to extract the carbon from Venus’s atmosphere to use as buckyfibre or diamond- based processing material - it could be adsorbed onto hot iron grains apparently, imported from Mercury of course;
there is a surface to space system called a Lofstrom loop which might work; you can us incoming ice from Callisto as a counterweight to help power the system,
but it is still inevitably a very power-hungry process compared to terraforming Mars, and would take a long, long time.
Oh, and it is best to leave the spin as it is, IMO;
it would be much more convenient to adjust the illumination by mirrors than use url=http://www.paulbirch.net/SpinAPlanet.zip]Birch’s particle beam planet despinners (unless you were feeling very profligate)
SF worldbuilding at
http://www.orionsarm.com/main.html
(TRY AGAIN)
it would be much more convenient to adjust the illumination by mirrors than use Birch’s particle beam planet despinners (unless you were feeling very profligate)
None would be a good choice. OK, for argument’s sake we’re going to ignore the staggering impracticalities of such an operation. But I’m afraid we can’t ignore the laws of physics as well.
If you shift the orbit of any one of the planets it will have an inevitable knock-on effect on the orbits of the rest, Earth included. So shifting Venus to make it more habitable is more than likely going to totally mess up the Earth’s habitability. The only way around this would be to alter the planet’s mass simultaneously. And that’s where things really start getting improbable.
I think that if you added enough water, the carbon dioxide would take care of itself. As long as you keep the insolation down with the mylar that is. Earth and Venus probably started with similar amounts of water, and they both have pretty similar amounts of carbon. The difference is that earth’s oceans didn’t boil away, and were available to help turn carbon dioxide into limestone. Venus had probably just enough sunlight to trigger a run-away greenhouse effect from the very beginning. The water vapor dis-associated into hydrogen and oxgen, and the hydrogen escaped into space. You would always have to keep Venus sheilded from the full intensity of the sun, or move it away, or else it would just revert to it’s natural hellish state.
Moving planets isn’t that hard, really. It’s possible to use a 100km or so asteroid to transfer momentum from Jupiter to the Earth or Venus. It’s just a little beyond our technical capabilities at this point.
As for moving one planet causing instabilities in the orbits of other planets, I imagine that the other planets would have to be carefully monitored and adjusted as neccesary, by the same means. The planets don’t really have that much of a gravitational influence on each other. Even when all the planets were recently aligned, their combined gravitation influence on the Earth was far far less that that of the sun or moon.
So when the Earth starts drifting out of orbit (and even the tiniest difference would dramatically change our climates) we’re going to smash an asteroid into it to fix things???
Bumping this up because I spotted it while doing a search for something else and noticed that no one answered this.
NASA has proposed sending a large asteroid past the Earth (think atmospheric grazingly close) to shift the Earth’s orbit. They were talking about doing this to back the Earth away from the Sun when the Sun starts to heat up in its final millions of years of life, but it could no doubt be used for the purpose you mention.
Science fictiony idea: If wormhole technology became practical (I love sentences that start like this) and we could open up a series of one million 50-meter-wide circular wormholes along Venus’s equator, and have the “outputs” of those wormholes arranged along Mars’s equator, how long would it take to bring Mars’s atmosphere up to, say, half Earth normal?
It is Nitrogen you want on Mars, not more carbon Dioxide; better to put the wormholes between Titan and Mars.
In fact if you have a three way link you could end up with a warm Titan and a cool Venus as well… interesting idea.
SF worldbuilding at
http://www.orionsarm.com/main.html
So we just fire up the infinite improbability drive, and voila!
Why with a 1920s style death ray of course
…I’m sorry but someone had to say it
Also, I’ve heard rumors that Mars needs women.
You can’t make an omlette without breaking a few eggs.
I don’t see a lot of value in farting around with Venus when Mars is so much easier to deal with. At least the Martian atmosphere won’t eat you.
Given that Mars has a very thin atmosphere, I’d say bombarding it with anything gaseous would be a good idea (except for overly toxic gasses, of course). At least with the CO[sub]2[/sub] injections, you’d have something for plants to work with to make oxygen. There might nitrogen trapped in Mars’s soil which could be liberated in some manner.
As for cooling down Venus using some kind of giant sunscreen, it probably wouldn’t take too terribly long, since BA estimates it’d only take six months for the Earth to be frozen solid if all light were cut off. So, given the fact that Venus is considerably hotter, has a thicker atmosphere, but it slightly smaller than the Earth, I’d think that it’d be just a few years or so before it turned into a Venuscicle.